Lock cylinder



R.y PERLICK LOCK CYLINDER Filed March 22, 1955 May 16, 1967 INVENTORRem/101.9 PzRL/c/f United States Patent 3,319,443 LOCK CYLINDERReinhold'Perlick, Velbert, Rhineland, Germany, assignor to Yale & TowneG.rn.b.H., Velbert, Rhineland, Germany, a corporation of Germany FiiedMar. 22, 1965, Ser. No. 441,633 6 Claims. (Cl. 70-421) ABSTRACT GF THEDISCLOSURE A lock tumbler cylinder in which a rotatable key plug ismounted in a lock operating sleeve that has a loose segment at thekeyway of the key plug. When a tool is inserted into the keyway forjamming the sleeve to the key plug, the tool will merely jam the sleevesegment to the outer cylinder body so that tumbler picking torque cannotbe applied through the sleeve to tumblers conrolling rotation of thesleeve. The segment further insures the etfect of a yielding detent thatnormally holds the sleeve in locking position.

The present invention concerns a lock cylinder with a key plug of knownconstruction carried rotatably in the cylinder housing and havingradially displaceable tumbler pins and a coupling tube rotatably carriedbetween the cylinder housing and the key plug, and presenting thefeature that the coupiing tube is restricted in its turning in relationto the cylinder housing by a braking element.

It is possible to defeat the usual lock cylinder by applying torque tothe key plug so as to take up lateral play between the tumbler pins andthe bores in which they move in the key plug and housing. The tumblerpins then are displaced one at a time by a suitable tool inserted in thekeyway, until each pin engages the housing at the parting line betweenthe housing and key plug. It is then possible to rotate the key plug.

In order to increase the security of lock cylinders, it is already knownto provide between the cylinder housing and the key plug a rotatablecoupling tube on which is the lock operating cam. The coupling tube hasseveral radial bores for the tumbler pins, and is normally blockedagainst turning by the pins. Certain of the tumbler pins have roundedends, so that it is more ditiicult to place the key plug under stressduring a picking operation. However, the coupling tube can also turnwith the key plug, and therefore it is possible with sufficient skill tobring the tumbler pins to the line dividing the tube and the housing sothat the lock, in spite of these measures, can be operated.

Acordingly, attempts have already been made to prevent the unauthorizedoperation of lock cylinders, as by making the keyway comparativelynarrow. However, the keyway must have sutcient width to allow the use ofa key of the necessary strength. Also, even when narrow, the keywaystill permits the unauthorized insertion of a suitable picking tool.Also, by the known method of forming the tumbler pins mushroom-shaped,the picking process can only be made difficult, but not prevented withany certainty.

By my invention, I am able to construct a lock cylinder with a key plugrotatably carried in the cylinder housing, having several radiallydisplaceable tumbler pins and a coupling tube rotatably carried betweenthe cylinder housing and the key plug and carrying the operating cam.which does not show the above-mentioned disadvantages. Rather, it isconstructed in such a way that it is substantially secure againstunauthorized operation. For this purpose, the invention provides thatthe coupling tube is restricted by a braking element in its turning inrelation to the cylinder housing. A lock cylinder of this type can onlybe operated with the properly constructed key and not with picking toolsof the usual type. In the rst place all the tumbler pins are so set bythe key that their contact points are at the cylindrical separating linebetween the cylinder housing and the coupling tube, so that accordinglythe pins lie across the separating line between the coupling tube andthe key plug, and the tube and the key plug are coupled together. Onoperation of the cylinder, accordingly not only the key plug but alsothe coupling tube is turned, against the action of the restrictingbraking element. On the other hand, if an attempt is made to pick thetumblers, the cylindrical key plug can still be put under stress, thatis to say turned slightly in relation to the housing, but the couplingtube will not turn with it, as this tube is prevented with certaintyfrom doing so by the braking element acting on the tube. Accordingly,when picking torque is applied to the key plug, a picking tool canmerely set the tumblers at the cylindrical separating line between thecoupling tube and the key plug, with the result that only the key plug,but not the tube carrying the operating cam, is turned, and the cylindercannot be operated.

In my preferred construction, the 'braking element consists of a detentsphere disposed in the cylinder housing and pressed by a spring, whichin the locking position of the coupling tube engages in a recessprovided in the wall of the tube, with the result that the brake effectarises in practice only in the locking position of the coupling tube,whereas the tube can rotate during the normal operation.

As an important feature of my invention, I construct my cylinder withmeans that will prevent the key plug becoming jammed up in relation tothe coupling tube by a specially constructed opening tool, withconsequent entrainment of the tube if torque is applied to the key plug.As a detailed part of this feature, the coupling tube has at its sideadjacent to the keyway in the cylinder core a longitudinal opening inwhich a segment-shaped insert is loosely carried. In this way, it isensured that any clamping forces applied at the keyway side are directlytransferred to the cylinder housing by the loosely carried insert, andaccordingly there are adhering forces applied between the coupling tubeand the cylinder housing so as to overcome the clamp forces between thetube and the key plug.

The invention will now be described in reference to the attacheddrawings, which show an embodiment but in no restrictive sense.

FIGURE 1 shows the lock cylinder of the invention with the key inserted,in longitudinal section.

FIGURES 2 and 3, show a cross-section of the cylinder withinserted keyand with an inserted picking tool.

The lock cylinder shown has a cylinder housing 1 and a cylindrical keyplug 2 constructed in the usual way and rotatably disposed therein,which key plug is provided with several tumbler pin bores 3 and a keyway4, for the insertion of a key. In the pin bores 3, tumbler pins 5 areslidably provided, which are in engagement with corresponding tumblerpins 6 which are disposed slidably in the openings 7 provided in thecylinder housing 1. The openings 7 are covered externally by a lockcasing 8 surrounding the cylinder housing 1. When the key 9 iswithdrawn, the housing pins 6 under the action of the springs 10 projectpartly into the pin holes 3 of the cylindrical key plug 2.

Between the cylinder housing 1 and the key plug 2 there is rotatablycarried a cup-shaped coupling tube 11, which at its inner end 11 isprovided with a shaft 12 for the closing cam 13, by which the lock,which is not shown in detail, can be operated. Further, the couplingtube 11 has radial bores 14 for the tumblers 5, 6. The rotation As canbe seen from FGURES 1 and 2, by the ini sertion of the key 9 into thekeyway d, the tumblers S, o are raised to the exent that thel contactpoints between the key plug pins and the housing pins e are aligned Withthe cylindrical separating line formed by the cylinder housing 1 and thecoupling tube il.. At the same time, the key plug 2 and the tube ll arecoupled together by the key plug pins 5. When rotated by the key,therefore, not only the cylindrical key plug 2 is turned, but also thecoupling tube ll, the lock being operated by the closing `cams 13carried by the tube.

If a person seeks to operate the cylinder without the proper key, hefirst will apply torque to the cylindrical key plug 2, as by utilizing apicking tool i7, FlG. 3. Thattorque will rotate the key plug 2 a slightamount, andinitially only to the extent permitted by the lateral playthat may exist between the tumbler pins o and the tumbler bores 3;, ld,and 7. The coupling tube lll on the, other hand' will not rotate becausethe tube will be held by the detent sphere 14a engaging in its recessl5., Therefore,4 while the torque will cause lateral pressures. on thetumblers 6,- those pressures will not be eil'ective. between thecylinder openings 7 and coupling tube,

openings 14. If the tumblers then are moved in an at-U tempt to detecttheir proper setting, the lateral pressures that are applied to thetumblers may be useful only to detect a setting of the tumblers at theline be-A tween key plug l2 and coupling tube il, as shown for ex amplein FG. 3. Through that procedure, it may be. possible to set thetumblers so that the cylindrical key plug 2 can freely turn, but on theother hand, the coupling: tube l with its connected cam cannot turn, andaccord-- ingly it is not possible to operate the cylinder. When the keyplug 2 has turned through 360, the housing. pins 64 again fall into thebores 3 of the cylindrical kegl ping 2 so that the key plug again islocked.

In order to prevent the `cylindrical key plug '/L being: jammed up inrelation to the coupling tube ll by the insertion of a tool in thekeyway nl, that is to say to pre vent the entrainment of the tube whentorque is applied to the plug, the coupling tube lll has on its sideadjacent, to the keyway 4 a longitudinal slit i8 in which there isloosely carried a segment-shaped insert l. More partie-- ularly, aperson attempting to detect the proper tumbleru setting may believe thathe can jam the key plug and'. al lower part of the coupling tube il toone another at the keyway 4i, in effect connecting tube ll and key plug21 so that they will rotate together, and defeating the pur-- pose oftube lll. However, in trying to iam the key plug;

- and tube, a person will press the segment shaped insert 1 9 in adownward direction against the housingT l, so that insert 19 a-ctuallywill oppose all rotating movements, Moreover, this insures that thedetent Ma will eiectively hold the coupling tube lll, so that the tubewill not be rotated when torque is applied for the purpose Oi detectingthe tumbler setting.

The coupling tube llll is covered at its outer end lll and at thesurface 11 of its inner end il', by discs of tempered steel 2u and 2l,which ensures that between the key plug 2 and the tube 1l no constantcoupling can be produced, for example by boring the key plug andinserting a tool.

I now claim:

1. In a combination of the class described, a lock cylinder, a sleeverotatable in a bore of said cylinder, means on said vsleeve foroperating a lock when said sleeve is rotated, a key plug rotatable insaid sleeve and having a longitudinal keyway terminating in alongitudinal slot on the outer surface of the key plug, a series oftumblers controlling the rotation oi said key plug relatively to alocking position in said sleeve and the rotation of said sleeverelatively to a locking position in thev bore of said cylinder, therebeing a possibility of picking: said tumblers through an application ofpicking torque tor the key plug, and means interposed between thelongi-v tudinal keyway slot and said cylinder when the sleevev and keyplug are in locking position, said interposed means being loosely heldin position by said sleeve for' preventing application of tumblerpicking torque to the sleeve by a tool inserted and manipulated throughthe keyway when said tool acts on said interposed means.

2. ln a combination of the class described, a lock cylinder, a sleeverotatable in a bore of said cylinder, means on said sleeve for operatinga lock when said sleeve is rotated, a key plug rotatable in said sleeveand having a longitudinal keyway terminating in a longitudinal slot onthe outer surface of the key plug, a series of tumblers controlling therotation of said key plug relaf tively to a locking position in saidsleeve and the rotation of said sleeve relatively to a locking positionin the bore of said cylinder, there being a possibility of picking saidvtumblers through an application of picking torque to the: .key plug,said sleeve having a slot wider than said keyway slot, the longitudinalcenters of said slots being substan tially aligned in the lockingposition of said key plug and. sleeve, and a guard assembled between thekey plug and the surface of the cylinder bore, said guard being looselyheld within said sleeve slot and substantially closing the'-longitudinal slot of the keyway, for preventing applicationl of tumblerpicking torque to the sleeve by a tool inserted and manipulated throughthe keyway when said tool actsI on said guard.

3. ln a combination of the class described, a lock' cylinder, a sleeverotatable in a bore of said cylinder, means on said sleeve for operatinga lock when said sleeve is rotated, a key plug rotatable in said sleeveand having a longitudinal keyway terminating in a longitudinal slot onthe outer surface of the key plug, a series of tumblers controlling therotation of said key plug relatively to a locking position in saidsleeve and the rotation of said sleeve relatively to a locking positionin the bore of said cylinder, there being a possibility of picking saidtumblers through an application of picking torque to the key plug, saidsleeve having a slot wider than said keyway slot, the longitudinalcenters of said slots being substantially aligned in the lockingposition of said key plug and sleeve, a guard assembled between the keyplug and the surface of the cylinder bore, said guard being loosely heldwithin said sleeve slot and substantially closing the longitudinal slotof the keyway, for preventing application of tumbler picking torque tothe sleeve by a tool inserted and manipulated through the keyway whensaid tool acts on said guard, and detent means yieldingly resistingrotation of said sleeve relatively to its locking position in saidcylinder,

4. ln a combination of the class described, a lock cylinder, a sleeverotatable in a bore of said cylinder, means on said sleeve for operatinga lock when said sleeve is rotated, a key plug rotatable in said sleeveand having a longitudinal keyway terminating in a longitudinal slot onthe outer surface of the key plug, a series of tumblers` controlling therotation of said key plug relatively to a locking position in saidsleeve and the rotation of said sleeve relatively to a locking positionin the bore of said cylinder, there being a possibility of picking saidtumblers through an application of picking torque to the key plug, meansinterposed between the longitudinal keyway slot and said cylinder whenthe sleeve and key plug are in locking position, said interposed meansbeing loosely held in position by said sleeve for preventing applicationof tumbler picking torque to the sleeve by a tool inserted andmanipulated through the keyway when said tool acts onsaid interposedmeans, and detent means yieldingly resisting rotation of said sleeverelatively to its locking position in said cylinder.

when the sleeve and key plug are in locking position, said.

interposed means being loosely held in position by said sleeve forpreventing application of torque to the sleeve relatively to saidcylinder by a tool inserted and manipulated through the keyway when saidtool acts on said interposed means.

6. In a combination of the class described, a lock cylinder, a sleeverotatable in a bore of said cylinder, means on said sleeve for-operating a lock when said sleeve is rotated, a key plug rotatable insaid sleeve and having a longitudinal keyway terminating in alongitudinal slot on the outer surface of the key plug, a series oftumblers controlling the rotation of said key plug relatively to alocking position in said sleeve and the rotation of said sleeverelatively to a locking position in the bore of said cylinder, thereibeing a possibility of picking said tumblers through an application ofpicking torque to the key plug, said sleeve having a slot wider thansaid keyway slot, the longitudinal centers of said slots beingsubstantially aligned in the locking position of said key plug andsleeve, a guard assembled in position between the key plug and thesurface of the cylinder bore, said guard being loosely held within saidsleeve slot and substantially closing the longitudinal slot of thekeyway, for preventing application of tumbler picking torque to thesleeve by a tool inserted and manipulated through the keyway when saidtool acts on said guard, and detent means yieldingly resisting rotationof said sleeve relatively to its locking position in said cylinder.

References Cited by the Examiner UNITED STATES PATENTS 1,261,089 4/1918Yawman 70-372 X 1,417,132 5/1922 Barker 70-364 1,989,327 1/1935Machinist 70364 2,111,098 3/1938 Segal 70-378 X 2,596,720 5/1952 Pastoret al 70-364 2,682,764 7/ 1954 Kotab 70-392 X 2,977,786 4/ 1961 Kendricket al 70-373 X FOREIGN PATENTS 1,154,732 9/1963 Germany.

718,451 11/ 1954 Great Britain.

MARVIN A. CHAMPION, Primary Examiner. P. TEITELBAUM, Assistant Examiner.

1. IN A COMBINATION OF THE CLASS DESCRIBED, A LOCK CYLINDER, A SLEEVEROTATABLE IN A BORE OF SAID CYLINDER, MEANS ON SAID SLEEVE FOR OPERATINGA LOCK WHEN SAID SLEEVE IS ROTATED, A KEY PLUG ROTATABLE IN SAID SLEEVEAND HAVING A LONGITUDINAL KEYWAY TERMINATING IN A LONGITUDINAL SLOT ONTHE OUTER SURFACE OF THE KEY PLUG, A SERIES OF TUMBLERS CONTROLLING THEROTATION OF SAID KEY PLUG RELATIVELY TO A LOCKING POSITION IN SAIDSLEEVE AND THE ROTATION OF SAID SLEEVE RELATIVELY TO A LOCKING POSITIONIN THE BORE OF SAID CYLINDER, THERE BEING A POSSIBILITY OF PICKING ANDTUMBLERS THROUGH AN APPLICATION OF PICKING TORQUE TO THE KEY PLUG, ANDMEANS INTERPOSED BETWEEN THE LONGITUDINAL KEYWAY SLOT AND SAID CYLINDERWHEN THE SLEEVE AND KEY PLUG ARE IN LOCKING POSITION, SAID INTERPOSEDMEANS BEING LOOSELY HELD IN POSITION BY SAID SLEEVE FOR PREVENTINGAPPLICATION OF TUMBLER PICKING TORQUE TO THE SLEEVE BY A TOOL INSERTEDAND MANIPULATED THROUGH THE KEYWAY WHEN SAID TOOL ACTS ON SAIDINTERPOSED MEANS.